A benchmark calculation is designed to compare the climate and climate sensitivity of atmospheric general circulation models (AGCMs). The experimental setup basically follows that of the aquaplanet experiment (APE) proposed by Neale and Hoskins, but a simple mixed layer ocean is embedded to enable air–sea coupling and the prediction of surface temperature. In calculations with several AGCMs, th...

The equilibrium climate sensitivity (ECS) has a large uncertainty range among models participating in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) and has recently been presented as ‘‘inherently unpredictable.’’ One way to circumvent this problem is to consider the transient climate response (TCR). However, the TCR among AR4 models also differs by more tha...

The ECHAM/MESSy Atmospheric Chemistry (EMAC) model is coupled to the ocean general circulation model MPIOM using the Modular Earth Submodel System (MESSy) interface. MPIOM is operated as a MESSy submodel, thus the need of an external coupler is avoided. The coupling method is tested for different model configurations, proving to be very flexible in terms of parallel decomposition and very well ...

The paper describes the evaluation of organic species concentrations as simulated by an atmospheric chemistry general circulation model. Overall it is a nice paper that deserves publication in ACP although there is a need for more detailed discussions at some places as further discussed in the following. Also in some cases, the rationales for choosing (or omitting) some sensitivity simulations ...

climate change is found to be the most important global issue in the 21st century, so to monitor its trend is of great importance. atmospheric general circulation models because of their large scale computational grid are not able to predict climatic parameters on a point scale, so small scale methods should be adapted. among downscaling methods, statistical methods are used as they are easy to...